There are five different OBD-II communication protocols:
- J1850 PWM
- J1850 VPW
Well, generally you will need to know which protocol you have when you buy a code reader or OBD-II tool. Sometimes manufacturers label the products for Ford, GM, etc. so it may be easy. However here is the quick way to tell what you have.
Note: At time of writing, I do not know if this is a 100% fool-proof method of telling what protocol you have. Be sure to check with a dealership or repair manual if in doubt.
To tell which protocol you have, see the table below: Standard Pin 2 Pin 7 Pin 10 Pin 15 Notes PWM must have – must have – The connector must have pins 2,4,5,10, and 16 VPW must have – – – The connector must have pins 2, 4, 5, and 16, but not 10. ISO – must have – may have The connector must have pins 4, 5, 7, and 16. Pin 15 may or may not be present.